There are many types of asthma, and also a few different classifications of this condition. Based on these classifications, your doctor can evaluate your treatment plan and recommend the best drugs. Knowing which type of asthma is also important for you, to avoid potential triggers.
The most common types of asthma are allergic asthma, non-allergic asthma, and occupational asthma. Let’s look at how these types of asthma are different from one another. Be aware that you may have one or more types – for example allergic asthma and exercise-induced asthma. This happens because the airways are hyperresponsive in asthma, which means they are very sensitive to irritants and respond in excess. This hyperresponsiveness leads to symptom aggravation not only from allergens but also respiratory infections, exercise, or tobacco smoke.
About 90% of children with asthma and half of adults with asthma have this allergic form of asthma. Allergic asthma is often associated with allergies and eczema, due to the so-called atopic march. The typical pattern starts with eczema, which is followed by food allergies, environmental allergies, and finally asthma. The typical symptoms of asthma: breathing difficulties, cough and wheezing tend to develop in addition to allergy symptoms like nasal congestion, itchy watery eyes, and sneezing. The symptoms are triggered by allergens such as pollen, mold, dust mites, and pet dander. Allergies to sulfites are common food allergens associated with allergic asthma. In addition to physical examination and lung function tests, it is important to also get allergy testing to identify the exact triggers. There are skin and blood allergy tests available. These tests should be repeated every few years, as new allergies may develop over time, while others may improve. The treatment includes anti-asthma drugs and antiallergic drugs like antihistamines or allergy shots.
Non-allergic asthma usually develops later in life and is caused by irritants like cold dry weather (or sudden changes in temperature or humidity), environmental pollutants, respiratory infections, stress, acid reflux, exercise, medication, or strong odors. There are no symptoms of allergies in this case, and the diagnosis is based on ruling out allergic reactions. In some cases, preventive medication like leukotriene modifiers and long-acting beta-agonists work better than inhaled corticosteroids.
Medication-induced asthma can be triggered by a variety of drugs, especially aspirin. These drugs act as triggers and can cause an acute attack or worsen pre-existing asthma. In some cases, the symptoms can be very severe, and even life-threatening.
Exercise-induced asthma is common and the symptoms typically develop during exercise and continue for several minutes after completing the workout. Using the rescue inhaler before exercising helps minimize the symptoms. Some individuals have other triggers that may worsen exercise-induced asthma such as sensitivity to cold weather, hot air, air pollution (when working outside), and strong odors (at the gym).
Occupation asthma and other forms of asthma
Occupational asthma is asthma triggered by various substances from the workplace. These substances can be allergens like dust, latex, paint, insects, chemical fumes, and gasses or irritants from the environment like chlorine, sulfur dioxide, and smoke. In this case, it is the work environment that triggers breathing difficulty, wheezing, cough, and other symptoms of asthma. Symptoms tend to be worse during work and improve during the days off. It is important to identify the triggers and use personal protective equipment like masks, gloves, and special clothes. In the US, the employer has the responsibility to protect employees from hazardous materials under the, as per the guidelines from Occupational Safety and Health Administration (OSHA)
Other types of asthma include cough variant asthma (when the cough is the only symptom of asthma), nocturnal asthma (when symptoms occur mostly at night), and corticosteroid resistant asthma (in which case the symptoms do not improve to corticosteroid drugs, and tend to be severe).
Types of asthma based on other criteria
Asthma can be classified based on the severity of the symptoms into intermittent, mild persistent, moderate persistent, and severe persistent. There are specific criteria to assess severity, taking into account how often do the symptoms develop, nighttime awakenings, the use of inhalers, how much the symptoms interfere with day to day life, important measurements of assessing lung diseases (FEV and FEV1/FVC), and risk of flare-ups requiring oral corticosteroids. The severity of asthma is assessed before the treatment is started because those who respond well to asthma drugs will have by definition, fewer symptoms. Note that this classification can’t predict how severe an acute attack of asthma is. Someone with mild asthma can develop a life-threatening acute flare-up for example.
Another classification is based on how well the symptoms are controlled, whether the asthma is mild, severe, or anything in between. The symptoms are assessed on those who receive treatment, and the goal is obviously to have well-controlled asthma. If not, asthma is classified as either not well controlled or very poorly controlled.